Changing 3 Gang 2-way switch to 2 Gang LightWaveRF smart switch

[FeelingOld]

Hi all, first time posting here so please go easy on me!

I've fitted single gang LightWaveRF switches before, but this is my first 2 Gang.

My setup in a kitchen diner, is 2 lights (one per area in room). The previous switch was a 3 Gang switch. I assume (don't know for sure) there must have been 3 lights originally, before the rooms were knocked through. One of the switches appeared to do nothing (wired into A1 - top left of Pic 1).

The existing switch looked like this:

Pic 1

• FeelingOld
• 8 Oct 2019

Pic 2

• FeelingOld
• 8 Oct 2019

Now I'm having issues once I've wired in the smart switch. The com has been wired into the live point. The other red wire (B1 on Pic 1) into one of the switch terminals, and the previously function black wire (C1 on Pic 1) into the second switch terminal. The tertiary black wire isn't wired into anything.

The switch engages and calibrates at this point. The dining light (red wire) works. Switches on and off and dims fine. The kitchen light (black wire) is controlled by the dining light. On if dining is on, off if dining is off. The switch it's plugged into has no effect.

I'm concerned I'm going to have to take up the upstairs carpet and re-wire the lighting circuit for this to work... Am I missing something?

Please help!

Thanks in advance

 

[JohnD]

looking at the wires, I think you only ever had two lighting circuits controlled by the switch.

Before you put in the Smart switch, I'd suggest you wire in a 2-gang 2-way switch and puzzle out the wiring.

2-way switches each have three terminals, arranged in a triangle.

The power comes in at the point of the triangle, and, depending on the position of the switch dolly, it goes out through one or other of the two terminals at the bottom.

Looking at your photo of the old switch, I think there might have been only one "in" wire, that got connected to both switches with short links. Is that right?

I think you have a reasonable chance of wiring up a simple 2-way 2-gang switch (it will only cost you a couple of pounds)
https://www.screwfix.com/p/mk-2-gang-2-way-10ax-light-switch-white/16201
after which you can identify and mark all the wires and hopefully, knowing what they are, be able to install your new one. A fine-point marker pen will be very helpful.

If you can lay your hands on a multimeter it will be much much easier.

Good work on photographing the old switch connections.

Edit

Looking at the wires, I think the switches were not being used as 2-way switching, but only as one way. I can only see two red wires and two black wires coming out of the wall. Is that right? Or do you have another switch at the other end of the room that controls the same lights?

 

[sparkwright]

Tertiary = Third.

Save you looking it up.

 

[FeelingOld]

Hey thanks for the quick reply!

Good advice, I'll get a cheap 2 gang switch to test... Does it have to be 2-way? My (limited) understanding is that it's wired like a 1-way would be. Any reason to get a 2-way over a 1-way?

Thanks

 

[JohnD]

no, I misled myself by thinking that the switch had been chosen for some sensible reason (it was probably just one that the installer had in his saddlebag). A 2-gang one-way switch should be all you need.

But you can use 2-way switches as 1-way if you want.

 

[winston1]

Hey thanks for the quick reply!

Good advice, I'll get a cheap 2 gang switch to test... Does it have to be 2-way? My (limited) understanding is that it's wired like a 1-way would be. Any reason to get a 2-way over a 1-way?

Thanks

2 gang switches are almost always 2 way.

 

[FeelingOld]

So, latest update (and I'm still scratching my head):

I ordered a 2 gang, 2 way switch to test as JohnD suggested:

Pic 3

• FeelingOld
• 9 Oct 2019

Pic 4

• FeelingOld
• 9 Oct 2019

These images are for the purpose of thoroughness; obviously with 1 COM in here, I didn't expect the Kitchen to work; it didn't, and the dining room did. No issues.

Pic 5

• FeelingOld
• 9 Oct 2019

Pic 6

• FeelingOld
• 9 Oct 2019

I created a short link from the Dining room COM to the Kitchen COM. Both worked independently then as they should, only when they were switched on each worked. I tried: 0|0, 0|1, 1|0, 1|1. All good.

Pic 7

• FeelingOld
• 9 Oct 2019

Pic 8

• FeelingOld
• 9 Oct 2019

I then tried the smart switch again. Wired as I would expect to have to wire it based on the previous 2 gang. It didn't work correctly; Dining room does, kitchen is always on.

The only thing I can think of is something to do with the markings on the smart switch "primary" & "secondary". I tried some settings in calibration menu on the app for it, but they didn't help (to be honest I was just guessing so maybe missed something). Either that, or it's potentially faulty? Perhaps it's defaulting to a multi-way setup that I don't actually need?

Any further advice would be great, thanks!

 

[EFLImpudence]

What do you think the N is for?


The switch requires a Neutral. You don't have one.

 

[FeelingOld]

The neutral wire is optional as per the lightwaverf wiring guide.

 

[EFLImpudence]

Do you mean it is just for 'parking' neutral wires? If so, sorry.

Then if the dining room light works and the other doesn't, I would agree that it appears faulty.

 

[EFLImpudence]

No, the N terminal is not a 'park'.

I don't know anything about these switches, but here -
https://support.lightwaverf.com/hc/en-us/articles/360012872491-Lighting-Smart-Series-
the remedy for several malfunctions is 'connect a neutral'.

 

[Chloe4479]

Did you ever fix the issue on this I noticed

You originally have 2 switch wires red and 2 switch live wires black.
Also the crossover wires

By removing those it won't work.

The new lightwave need only 1 live wire becuase they presume you have new wiring in the rose or cealing.

On the new dimmer u need both blacks on the outside this is the swith live. Then connect both reds togther and join both into the one marked L.

The N is not used as this is netrual for interlal 12v wiring.

Be good to see if that was the issue